Conical pendulum.



Patented July 29, I902.

F. m. CLARK.

GONICAL PENDULUM.

(Application filed Feb. 19, 1901.)

(No Model.)

UJITJF EEEES #WQM' UNITED STATES PATENT OFFICE.

FRANK M. CLARK, OF TILTON, NEW HAMPSHIRE, ASSIGNOR TO GEORGE Ii. CLARK,OF WORCESTER, MASSACHUSETTS.

CONICAL PENDULUM.

SPECIFICATION forming part of Letters Patent N 0. 705,647, dated. July 21902- Application filed February 19, 1901. Serial No. 47,971, No model.)7

To ctZZ whom it may concern: of this worm is stopped at p, as the thrustis Be it known'that I, FRANK M. CLARK, of upward. In alinement with thisworm and Tilton, county of Belknap, State of New below it there is aspirally-wound spring .2, Hampshire, have made certain new andusemounted on a bracket g, secured to the clock- 55 5 ful Improvementsin Conical Pendulum frame. The lower end of the spring is fast Clocks,of which the following is a descripin a cup 7c, secured to the outer endof said tion sufficiently full, clear, and exact to enbracket. The upperend of said spring is free able any person skilled in the art or scienceand a cupj is fast thereon. The pendulumto which said inventionappertains to make rod C is pendent from this upper cup j, being 60 Iand use the same, reference being had to the offset at 7L to pass aroundsaid spring and under accompanying drawings, forming a part of thebracket, so that when at rest the body of this specification, in whichsaid rod will be in alinement with the worm q. Figure 1 is a frontelevation of a clock pro- On the lowerendapear-shaped weightfis fast.vided with my improvement, the lower por- From the upper end of the rodC and in aline- 65 tion of the case being glazed to show the penmenttherewith a needle t' projects vertically. dulum; Fig. 2, an elevationshowing the On the lower end of the worm q a horizontal method ofmounting and driving the penducrank-arm r is fast. To the outer end ofthis lum; Fig. 3, a side elevation showing the arm one end of aconnecting-rod sis pivoted crank and connecting rod, and Fig. i a diabya crank-pin t. In the outer end of this 70 gram illustratingthemovements of the same. connecting-rod there is a flaring opening 1),Like letters and figures of reference indi- Fig. 3, in which the upperend of the needle cate corresponding parts in the different figt playsand is directed by the movements of ures of the drawings. said crank. Asthis connection projects lat- My invention relates especially to thaterally from the worm, it will readily be seen 75 class of clocks knownas noiseless, wherein that by slipping the needle end in this openthereis a rotary escapement and in which the ing the pendulum C is thrown outof alinependulum has a continuous conical movement with the worm and isheld at an angle, ment, the object being particularly to proas shown inFig. 2. vide a simple, cheap, and effective device Centrally inthebottom 15 of the clock-case 80 whereby the pendulum may be drivenfrom there is a starting device. This consists of a its upper end, sodirected that its weight will vertical shaft 16, journaled in saidbottom be maintained in an even circular course and and provided with acrank-handle 17. Withthat its mount shall compensate for variain thecase adisk 18 is fast on said shaft and. tions in length caused bytemperature. the pendulum-weightfnormally rests against 85 The natureand operation of the device will the periphery of this disk when theclock is be readily understood by all conversant with run down.Surrounding this disk is a circusuch matters from the followingexplanation. lar cup-shaped guard, which determines the In the drawings,A represents a clock-case outward movement of the pendulum-weight. ofordinary construction and provided in its In the diagram shown in Fig.ithe circle to oo lower face with a glazed opening B, through representsthe periphery of the starting-disk, which the pendulum C is exposed. Thelegs the circle y the circle of the guard-cup, and cl are provided withleveling-screws b. The the circle a: the normal circle of travel of themain works of the clock are of the usual conpendulum-weight. To maintainthis weight struction andarrangement and providedwith in such course atand keep it at all times 95 a rotary escapement-wheel D. Hence it istraveling in asubstantially perfect circle, the not deemed essential toherein particularly crank movement is designed. The connect show ordescribe the same. ing-rod S is therefore so arranged'that when Inbearings m m within the case and arthe end of the needle t' is disposedin its free ranged Vertically there is mounted a spiral end and theweight f is resting against the 1'00 worm q, meshed with the teeth ofthe scape disk 18 said connecting-rod is nearly on the wheelD and driventhereby. The upper end line of a tangent to the circle to, as shown,

and leads out to tangent of circle a' in motion.

In operation to start the clock the handle 17 is rotated. The frictionof the disk 18 against the weightf carries it in circular motion, whichgradually widens in diameter until the course of travel of said weightis in the circle x. The escapement-wheel D being driven by themainspring in the usual manner, the worm q is rotated, thereby drivingthe crank in a perfect circle and carrying the upper end of the needle1? also in a circle concentric with the weight course with which thecrank is tangent. As the natural tendency of the weight f is to fallinto an elliptical course in its conical rotation, this precise movementof the connecting-rod exerts pull or pressure on the upper end of theneedle at the proper times and maintains the movement of the Weight in acircle in a manner which will be obvious to those conversant with suchmatters without a more explicit description. It will be noted that thefulcrum or pivoted center of the pendulum is the center of the spring 2.By supporting or cushioning the pendulum on said spring and driving itfrom the upper end I not only simplify the needed mechanism, but I alsoin a very appreciable measure regulate the clock, for the variations ofthe pendulum-rod through temperature are very closely compensated for bythe variations in opposite direction (on account of position) of thespringefor like causes. Ifind, moreover, in practice that a clockconstructed as described runs nearly twice as long with the same tensionof mainspring as it Will when the ordinary reciprocating pendulum isemployed. One cause of this is the radical reduction of friction in theescapement, the movement of which is continuous with the There is alsono noise, as results from the contacting of the detent ordinarily used,and where a clock would ordinarilystop when the mainspring is littlemore than one-half expanded in this device the expansion, and hence thedriving power, is extended until the spring is practically dead.

Having thus described my invention, what I claim is- 1. In a clock aconical spring arranged with its base-coil horizontally nearer theclock-base than is its apex; a comically-moving pendulum supported fromthe apex of said spring; and devices for driving said pendulum from itsupper end substantially as described.

2. In a clock a conical spring arranged with its base-coil horizontallynearer the clock-base than is its apex; a conically-moving pendulumsupported from the apex of said spring; a worm driven by the scape-wheelof said clock and a crank connection between the upper end of saidpendulum and said worm whereby the pendulum may be guided positivelyabove its point of suspension substan tially as specified.

3. In a clock the pendulum, C, in combination with the spiral, .2,supporting said pendulum; the escape-wheel, D, and mechanism actuated bysaid wheel for guiding the end of said pendulum above its fulcrum-pointin a circle.

l. Inaclockprovided withaconically-moving pendulum the case incombination with the crank-actuated disk disposed in position to contactthe pendulum-weight when at rest.

5. In a clock of the class described the case; the crank-actuated disk;18; and the encircling guard, 10, arranged as specified.

FRANK M. CLARK. Witnesses:

H. P. Ronnn'rs, O. M. SHAW.

